1. Field of the Invention
Embodiments of the present inventions relate to suturing devices and methods. Specifically, preferred embodiments of the present inventions relate to suturing devices and methods for suturing a patent foramen ovale.
2. Description of the Related Art
Health practitioners frequently use sutures to close various openings such as cuts, punctures, and incisions in various places in the human body. Because of their importance and frequent use, several types of sutures and devices for their implantation and extraction have been developed. These devices include needles having various shapes and sizes as well as devices for inserting and removing staples. Generally, sutures are convenient to use and function properly to hold openings in biological tissue closed thereby aiding in blood clotting, healing, and prevention of scaring. However, there are some circumstances under which it is not feasible to use conventional sutures and suturing methods to close an opening. Some of these circumstances occur with incisions in arterial walls, or other internal bodily tissues. Here, catheter based devices and procedures have been suggested to close such openings.
For example, during development of a fetus in utero, blood is generally oxygenated by the mother's placenta, not the fetus' developing lungs. Most of the fetus' circulation is shunted away from the lungs through specialized vessels or foramens, such as the foramen ovale. The foramen ovale is a flaplike opening between the atrial septa primum and secundum which serves as a physiologic conduit for right to left shunting between the atria. Typically, once the pulmonary circulation is established after birth, left atrial pressure increases, resulting in the fusing of the septum primum and septum secundum and thus the closure of the foramen ovale. Occasionally, however, these foramen fail to close and create hemodynamic problems, which may ultimately prove fatal unless treated. A foramen ovale which does not seal is defined a patent foramen ovale, or PFO.
To close such PFOs, open surgery may be performed to ligate and close the defect. Such procedures are obviously highly invasive and pose substantial morbidity and mortality risks. Alternatively, catheter-based procedures have been suggested which involve introducing expandable structures through the patent foramen ovale to attempt to secure the tissue surrounding the patent foramen ovale, thereby blocking and sealing the patent foramen ovale. However, these structures involve support structures which may fail during the life of the patient and/or become dislodged, thereby re-opening the patent foramen ovale and possibly releasing the structure within the patient's heart. Thus, it would be advantageous to provide a simple, closure device and procedure for sealing a patent foramen ovale.